title: Ex vivo gene delivery of ephrin-B2 induces development of functional collateral vessels in a rabbit model of hind limb ischemia.
abstract: OBJECTIVE
  In this study, we delivered ephrin-B2 to the ischemic hind limb of rabbits using an ex vivo method of gene transfer and evaluated whether the in vivo application of ephrin-B2 contributed to the development of functional collateral vessels. Ephrin-B2 is a transmembrane ligand of several Eph receptors and bidirectional signaling between ephrin-B2 and Eph-B4 is considered to be essential in angiogenesis and the development of arteries and veins.
  
  
  METHODS
  The left femoral artery of male Japanese White rabbits was excised to induce limb ischemia, and a primary culture of autofibroblasts was obtained from a skin section. Nineteen days later, the gene expressing ephrin-B2 (ephrin group) or beta-galactosidase gene (control group) was adenovirally transfected to the cultured auto-fibroblasts (5 x 10(6) cells); then 48 hours later, the gene-transduced cells were injected through the left internal iliac artery of the same rabbit. At 28 days after injection, the development of collateral vessels and their function were assessed (control group, n = 12; ephrin group, n = 10).
  
  
  RESULTS
  The gene expressing ephrin-B2 was successfully transferred to the rabbit autofibroblasts, and ephrin-B2, expressed on the cell membrane, possessed binding ability with its receptor, Eph-B4. Calf blood pressure ratio (control group: 0.523 +/- 0.047 vs ephrin group: 0.658 +/- 0.049, P < .0001), angiographic score (0.344 +/- 0.091 vs 0.525 +/- 0.109, P = .0006), in vivo blood flow of the left internal iliac artery (rest: 11.963 +/- 2.806 vs 17.202 +/- 3.622 mL/min, P = .0014; maximum: 27.652 +/- 10.377 vs 43.400 +/- 7.108 mL/min, P = .0007), collateral conductance (32.740 +/- 7.408 vs 54.489 +/- 18.809 mL/min/100 mm Hg, P = .0097), and capillary density of the left thigh muscle (118.517 +/- 18.669 vs 167.400 +/- 31.271, P = .0002) showed significant improvement in the ephrin-B2 group compared with controls.
  
  
  CONCLUSIONS
  These findings suggest that auto-fibroblasts expressing ephrin-B2 potentially promote arteriogenesis as well as angiogenesis in the adult vasculature, resulting in the development of functional collateral vessels to an ischemic lesion.
authors.affiliation: Department of Vascular Regeneration, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Masatake
authors.initials: M
authors.lastname: Katsu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koyama
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Maekawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurihara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Uchida
authors.forename: Hirohumi
authors.initials: H
authors.lastname: Hamada
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001794:Blood Pressure; D002196:Capillaries / Q000378:metabolism / Q000503:physiopathology; D002478:Cells, Cultured; D003097:Collateral Circulation; D004195:Disease Models, Animal; D036388:Ephrin-B2 / Q000096:biosynthesis* / Q000235:genetics; D005347:Fibroblasts / Q000378:metabolism / Q000637:transplantation*; D015316:Genetic Therapy; D005822:Genetic Vectors; D006614:Hindlimb; D007511:Ischemia / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D051379:Mice; D008833:Microcirculation; D018482:Muscle, Skeletal / Q000098:blood supply*; D018919:Neovascularization, Physiologic; D011817:Rabbits; D011859:Radiography; D036224:Receptor, EphB4 / Q000378:metabolism; D012039:Regional Blood Flow; D013997:Time Factors; D014161:Transduction, Genetic
chemical_list: D036388:Ephrin-B2; D036224:Receptor, EphB4